For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningInstallation Procedure
Remove all mounds or loose pieces of urethane adhesive from the
pinch-weld area.
Inspect for any of the following problems in order to help prevent
future breakage of the window:
High weld
Solder spots
Hardened sealer
Any other obstruction or irregularity in the pinch-weld fla ...
Installation Procedure
Note: If the location of the original plug weld holes can not be
determined, space the plug weld holes every 40 mm (1½ in).
Drill 8 mm (5/16 in) for plug welding along the edges of the rear floor
panel filler as noted from the original
panel.
Clean and prepare the atta ...
Roadside Assistance Program
For U.S.-purchased vehicles, call 1-800-243-8872; (Text Telephone (TTY): 1-888-889-2438).
For Canadian-purchased vehicles, call 1-800-268-6800.
Service is available 24 hours a day, 365 days a year.
Calling for Assistance
When calling Roadside Assistance, have the following information ready:
• ...